Hydrogel materials are used in culturing tasks where hydrophilic supporting material is needed, and for example agar type hydrocolloids are widely used in plant cell, bacterial, and fungi culturing for various microbiological purposes.
Agar is a linear and non-ionic polysaccharide consisting of D-galactose and 3,6-anhydro-L-galactose and it is produced from seaweeds. In solid cultures suspensions of microbial cells are spread onto the surface of the agar hydrogel, typically containing 1.5 wt % of agar, and nutrient fluid. The microorganisms grow and form macroscopic colonies, which can be separated and pure cultures may be obtained. The use of solid agar plates provides two-dimensional growth and the separation of colonies requires mechanical cutting etc.
Several alternatives for the use of agar plates have been proposed, for example gellan gum produced by Pseudomonas elodea. Gellan gum is soluble in hot water, and it forms a stiff gel upon cooling and shows improved stability at higher temperatures. Hydrogels based on gellan gum are very sensitive to nutrients and additives and require careful formulation of the medium.
In Deguchi, S. et al., Preparation and characterisation of nanofibrous cellulose plate as a new solid support for microbial culture, Soft Matter, 2007, Vol. 3, No. 9, s. 1170-1175, a cellulose plate is suggested for solid culture of microorganisms where the cellulose was obtained by dispersing microcrystalline cellulose in an aqueous saturated solution of Ca(SCN)2 to form a complex between cellulose and calcium thiocyanate ions, followed by dissolving the cellulose by heating, and obtaining a viscous solution. Said solution was then poured into a culture dish, allowed to solidify whereby cellulose was recrystallized, followed by washing with methanol and water. After washing the gelation was fixed. The pores of the plates were filled with an appropriate nutrient fluid. E. coli, B. subtilis, and S. cerevisiae as well as T. thermophilus grew on the cellulose plates.
U.S. Pat. No. 5,254,471 discloses a carrier for culturing cells, made of ultrafine fibers. WO 2009/126980 discloses cellulose-based hydrogel, which contains cellulose exhibiting an average degree of polymerization of 150-6200.
Existing cell culture biomaterials do not allow transferring the hydrogel matrix with a needle without seriously damaging the cultured cells.
In connection with microbial culture, fermentation, and microbial sample storage, detection as well as enumeration and quantification of microbes, based on techniques where real-time polymerase chain reaction (PCR) is carried out, are widely used. In PCR the microbes are broken down to release their DNA and the DNA is thereafter quantified by using specific oligonucleotide primers, thermo-stable DNA polymerase and appropriate thermal cycler. Many agents and substances, present in culture materials or polymeric materials inhibit the PCR reactions and make microbial quantification unreliable. Typically such materials are used as fermentation media, culturing media, sample storage matrix, fermentation enhancers, and transportation matrix, where said materials interfere with the detection and quantification procedures.
Thus there exists a need to provide improved culture compositions, matrixes and methods for microbial culture where the disadvantages relating to the materials of state of the art can be avoided or at least substantially decreased.